Recyclerview网格布局项装饰以显示

Question

我有一个使用gridlayout的recyclerview，如下所示。我想以这样一种方式设置项目装饰，即每行显示4个项目，并带有边框，并且边框之间没有空格。

recyclerView = findViewById(R.id.gridItems);
    List<Amenity> amenities = createAmenities();
    AmenitiesGridAdapter amenitiesGridAdapter = new AmenitiesGridAdapter(AmenitiesActivity.this, amenities);
    recyclerView.setLayoutManager(new GridLayoutManager(AmenitiesActivity.this,4));
    recyclerView.setAdapter(amenitiesGridAdapter);

我还有物品装饰，可以为recyclerview设置如下图所示

AmenitiesItemDecoration lineService = new AmenitiesItemDecoration(this, 4, amenities.size());
recyclerView.addItemDecoration(lineService);

下面是我的物品装饰课

public class AmenitiesItemDecoration extends RecyclerView.ItemDecoration{
private int[] attrs = new int[]{
        android.R.attr.listDivider
};
private Drawable divider;
private int mColumn;
private Context mContext;
private int mTotalCount;
private boolean isAllScreen = true;

public AmenitiesItemDecoration(Context context, int column, int totalCount) {
    super();
    mContext = context;
    TypedArray typedArray = context.obtainStyledAttributes(attrs);
    divider = typedArray.getDrawable(0);
    mTotalCount = totalCount;
    mColumn = column;
}

public void isAllScreen(boolean isAllScreen) {
    this.isAllScreen = isAllScreen;
}

@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
    super.onDraw(c, parent, state);
    drawLine(parent, c);
}

private void drawLine(RecyclerView parent, Canvas c) {
    Paint paint = new Paint();
    paint.setColor(mContext.getResources().getColor(R.color.colorAccent)); //#FF4081
    paint.setStrokeWidth(Px2DpUtil.dp2px(mContext, 1.5f));
    int childCount = parent.getChildCount();
    mTotalCount = parent.getChildCount();
    for (int i = 0; i < childCount; i++) {
        View childView = parent.getChildAt(i);
        float x = childView.getX();
        float y = childView.getY();
        float width = childView.getWidth();
        float height = childView.getHeight();

        if (i % mColumn == 0) {
            View view = parent.getChildAt(i);
            float x1 = view.getX();
            float y1 = view.getY();
            //top
            c.drawLine(x1, y1, ScreenUtil.getScreenWidth(mContext), y1, paint);
        }

        if ((i + 1) % mColumn != 0) {
            //right
            c.drawLine(x + width, y, x + width, y + height, paint);
        }

        int remainder = mTotalCount % mColumn;
        int temp = mTotalCount - i;
        if (isAllScreen) {
            if ((temp <= remainder) || (temp <= mColumn && remainder == 0)) {
                //bottom
                c.drawLine(x, y + height, ScreenUtil.getScreenWidth(mContext), y + height, paint);
                //right
                c.drawLine(x + width, y, x + width, y + height + divider.getIntrinsicHeight() / 2, paint);
            }
        } else {
            if ((temp <= remainder) || (temp <= mColumn && remainder == 0)) {
                //bottom
                c.drawLine(x, y + height, x + width, y + height, paint);
                //right
                c.drawLine(x + width, y, x + width, y + height + divider.getIntrinsicHeight() / 2, paint);
            }
        }
    }
}

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State
        state) {
    int left = 0;
    int top = 0;
    int right = 0;
    int bottom = 0;
    int position = parent.getChildLayoutPosition(view);
    int remainder = mTotalCount % mColumn;
    int temp = mTotalCount - position;
    if ((temp <= remainder) || (temp <= mColumn && remainder == 0)) {
        bottom = divider.getIntrinsicHeight();
    }
    outRect.set(left, top, right, bottom);
  }
}

我的挑战是物品装饰正在显示，我不确定我在哪里种植它。